1 Parameter Controlled By Multple Combo Boxes On A Form

Hi

I have been trying to set up this query via VBA code but, with no luck, have gone back to the query in design view. Basically the parameters of the query are determined by combo boxes in a form. This is fine if one combo box indicates one criteria but a problem arisis when multiple combo boxes are possible parameters for one field.

i.e. Field 1 = combo box one
field 2= combo box two
field three = combo box three, four or five.

i have found it difficult running this, especially in terms of a returning all if a combo is left blank. the problem with setting this up on field three would be that if i run combo box four and five to return all if left blank it overides the other command to set a specific parameter. Also, for some reason i can tdecide whether this is an AND or OR command, its actually both i.e. Field three parameter = combo box three and/or combo box4 etc...

please help this is driving me crazy.

Thanks

Shapman